This invention relates generally to metal cutting machine tools and more specifically to a metal cutting machine tool which performs both turning and machining center operations on an unfinished workpiece.
In many industrial applications, it is desirable to perform both a turning operation as well as one or more machining center operations, such as drilling, milling, tapping, or reaming, etc. on an unfinished workpiece. Until quite recently, accomplishing both turning operations and machining center operations on a single workpiece required separate machines for each type of operation. In addition to the expense of maintaining separate machines for performing turning and machining center operations, a transport system must be provided for transferring parts from one type of machine to another. During part transfer, the machines are idled, resulting in machine inefficiency.
Recently, machine tools, such as the Kearney & Trecker Model "Milwaukee Matic Turn 12" machining center as described in the Mar. 24, 1969 edition of American Machinist, have been developed to perform both machining center and turning operations on a workpiece. To accomplish both turning and machining center operations, the Kearney & Trecker "Milwaukee Matic Turn 12" machining center includes a headstock driven by a hydraulic motor and a rotatable spindle positioned opposite the spindle and driven by an electric drive. An automatic tool changer is mounted adjacent to the spindle and holds both turning tools and cutting tools for effectuating turning and cutting operations, respectively. Although the machining center described above is well suited for performing both turning and machining center operations, the above-described prior art machining center requires separate drives for the spindle and headstock, thereby increasing machine complexity and machine cost.
In contrast, the present invention concerns a machining center for performing both turning and machining center operations having but a single spindle drive system thereby reducing machine complexity and cost.
It is an object of the present invention to provide a machine tool having but a single spindle drive system for performing both turning and machining operations on a workpiece.
It is another object of the present invention to provide a single spindle machine tool, operable as both a chucking type lathe and as a machining center, having a storage drum thereon for holding both toolholders and workpiece holders.